The present disclosure relates generally to lighting apparatus and in particular to a total internal reflection (TIR) lens with an integrated lamp cover.
The incandescent light bulb is over 100 years old. While it is still in widespread use, much effort is being directed to replacing incandescent bulbs with more energy-efficient lighting technologies such as compact fluorescent bulbs or lamps based on light-emitting-diodes (LEDs).
One challenge facing these new technologies is integration with the substantial infrastructure that supports incandescent bulbs. For example, many existing light fixtures provide standard threaded sockets into which an incandescent bulb having a standard threaded screw base can be inserted, allowing the user to easily replace a burned-out bulb. Most buildings have permanently installed light fixtures, such as “can” lights mounted into ceilings, “track” lights in which individual light fixtures can be positioned along a track, and so on. These fixtures are often designed to accommodate incandescent bulbs having various standard form factors.
One example of a standard light-bulb form factor is “PAR-38.” This term of art refers to a bulb with a parabolic aluminum reflector, a transparent or translucent front cover that allows light to escape, and a diameter of 38 eighths of an inch (4.75 inches, or 107.95 millimeters (mm)). PAR-38 light bulbs are commonly used in applications such as recessed light fixtures, security lights, spotlights, or other applications where directed light is desired.
To facilitate conversion from incandescent bulbs to newer technologies, it is advantageous to make lamps based on LED or other energy-efficient technology that have form factors and screw-threaded bases compatible with existing fixtures designed for incandescent light bulbs, thereby eliminating the expense and difficulty of replacing existing light fixtures in order to accommodate new types of lighting.
To be successful as a replacement for existing light bulbs, an LED-based lamp should have a form factor approximating that of the light bulb to be replaced and external electrical connections compatible with existing light fixtures. In addition, the lamp should be robust, provide a satisfactory light quality, and have an attractive appearance.